Concrete safety mining unit



Aug. 22, 1933.

J. M DOUGALL CONCRETE SAFETY MINING UNIT Filed Dec. 30, 1930 pug" ejohn/Ma ouyall a4 ATTORNEY;

engage recesses in the long blocks located under in theiespeotive blocks, and bonding ate e "Patented Aug. 2 2, I 3 w v UNITED STATES PATENT OFFICE 1,924,044 CONCRETE SAFETY MINING UNIT John MacDougall, Wyoming, Pa.

Application December 30, 1930 Serial No. 565,591

1 Claim. (01. 72- 72) This invention relates to a pillar for supportshort blocks engaging recesses in said short ing roofs of mines so that all the coal can be reblocks. Thus all the blocks are firmly locked moved from the mine without leaving portions together and there is no danger of the units slipto form supporting pillars, the general object of ping out of place.

5 the invention being to provide a plurality of units Anyv suitable kind of mortar or molders loam for forming the pillar, the units being so formed can be placed between the blocks and this acts as that they can be assembled by unskilled labor a Cu io a binder for the D -t and the pillar made of any desired height, and A filling of rock or any other suitable material the units being ofsuch material that there is no can be place in t hollow p as shown at p 10 danger of the pillar deteriorating. I 5 in Figure 4 and the blocksmay be provided This invention also consists in certain other W t rei cing steel, a shown at 5 in re features of construction and in the combination 3 and 4. I r

and arrangement of the several parts, to be here- 7 This p as before stated, pp the roof inafter fully describedgillustrated in the accomof a mine and enables the removal of coal which panying drawing and specifically pointed out in has hitherto been left to form pillars' As the the appended claim. pillars are made of reinforced concrete, there is nov Indescribing the invention in detail, reference chance of disintegration as there is When p Will be had to e acco panying drawing Wherelal's are formed of'coal or wood and thus there is in like characters denote like or corresponding n danger f the f collapsing ft a course 20 parts throughout the several views, and in of timewhich: a i It is thought from the foregoing description Figure 1 is an elevation of a-pillar constructed. that the advantages and novel features of the in accordance withthe invention. invention Will be readily pp t- Figure 2 is a perspective view of a modified It is to he understood that s e s'may ,b 35 form of, pillar. j made in the construction and in the combination Figure 3 is a perspective i h wi f h and, arrangement of the several partsprovided of the units provided with reinforcing means; that Such changes e l With t scope of the Figure 4 is a sectional view through the hollow apliended Claimpillar shown in Figure l. I I What I claim is:--

30 Figure 5 shows in perspective a number of the A concrete a ty minin u o isi a blocks forming the h ll n g pillar formed of a plurality of block-like units v Referring to the drawing-in detail, the pillar imposed one upon the other. to providefluniform Shown may b fonned hollow as in Figures and straight vertical walls to the pillar at all sides 4 d in'thi f each it is comp osedkfi the 2 thereof, each unit composed of a plurality of four blocks 1', the blocks at opposing sides being 7 long and short blocks, the blocks of each it b longer than the blocks at the other sides so that 1 placed in a row and the blocks of t next the short blocks will fit between the ends of the unit placed at r.ight angles to the blocks of the long blocks. The units of the hollow pillar are first unit whereby the units are a r y a1"- also alternately arranged, as shown in Figure 2. ranged With the blocksof alternate units extend- 40 Each block is formed with th je t 3 on ing 'at'right angles to the blocks of the other units.

its lower face for engaging recesses 4 on the upper lugs o m on the lo face f each meek, each face of an under block so that the blocks are h i leoesses'ih the pp face, whereby locked togetherby' the projections and recesses. d blocks e looked together by the ihter- As shown in Figure 5, projections one long block fitting the s i the reoesses, reinforcements the first mentioned long blocks, with the proarranged betweensthe blocks, the lugs and rejections on the short blocks engaging recesses in cess s b in f r sp d sizes w sp t the long blocks located under them and with to "each other andof wedge formation 50 projections on the long blocks placed "over the i JOHN MACDOUGALL. 

